Originally Posted by

**rpenmanparker**
Exponential is the change from 100 to 1,000, i.e. 10e2 to 10e3 on one axis while a linear change occurs on the other axis. Actually since the x-axis is qualitative, not quantitative, there is no numerical relationship between them at all. So I will LOL too. But I get the gist of what OP was trying to say. Like you would number the groups (group sets, gruppos...) 1, 2, 3, ,4, 5...Then you plot that against the prices and get an exponential relationship. There is no squared relationship required for this situation to be exponential by definition.